CN115492939A

CN115492939A - Butterfly valve

Info

Publication number: CN115492939A
Application number: CN202211420131.6A
Authority: CN
Inventors: 吕国钦; 杨淼淼; 范龙广; 齐玉强; 李鹏; 李振; 李功超
Original assignee: Shandong Yibaitong Valve Co ltd
Current assignee: Shandong Yibaitong Valve Co ltd
Priority date: 2022-11-14
Filing date: 2022-11-14
Publication date: 2022-12-20
Anticipated expiration: 2042-11-14
Also published as: CN115492939B

Abstract

The invention discloses a butterfly valve, which relates to the field of valves and comprises a valve pipe, a valve rod and a valve plate, wherein two ends of the valve pipe are coaxially, rotatably and hermetically connected with end pipes, and a first connecting rod is fixedly connected between the two end pipes; one end of the valve rod is connected with a bevel gear, and a bevel gear ring meshed with the bevel gear is fixedly connected to the end pipe; the edge of the valve plate is provided with a sealing air bag, the other end of the valve rod is sleeved with a piston rod in a sliding mode, a first piston cavity communicated with the sealing air bag is arranged in the valve rod, a first piston is connected in the first piston cavity in a sliding mode, the inner end of the piston rod is fixedly connected to the first piston, the outer end of the piston rod is provided with a propping part, a stop block is fixedly connected to the end pipe, an arc-shaped track is arranged on the stop block, the arc-shaped track extends around the center of the valve pipe in an eccentric mode, a first spring is sleeved on the piston rod, and the propping part is driven by the first spring to be pressed into the arc-shaped track; the valve pipe is sleeved with a rotary cylinder at intervals, and a second connecting rod is fixedly connected between the valve pipe and the rotary cylinder. The invention has good sealing effect, is not easy to wear and occupies small space.

Description

Butterfly valve

Technical Field

The invention relates to the technical field of valves, in particular to a butterfly valve.

Background

Butterfly valves are one of the most common types of valves used in the valve industry for the regulation and control of fluids. The valve plate of the conventional butterfly valve is disc-shaped, and the valve plate rotates under the driving of the valve rod to realize the opening and closing of the valve.

The butterfly valve is divided into a soft seal butterfly valve and a hard seal butterfly valve, the hard seal butterfly valve is suitable for high-temperature and corrosive environments, and the seal pair of the hard seal butterfly valve is made of metal materials, so that the sealing effect is poor; and the vice one side of sealing of soft seal butterfly valve is metal material, and the opposite side is elastic non-metal material, and soft seal butterfly valve is sealed effectual, but non-metal material easily wears out, in case wear out seriously, just can lose efficacy by the sealed vice, influences the butterfly valve performance. Moreover, the valve rod of the soft seal butterfly valve extends out along the radial direction and is connected with the knob, so that the whole butterfly valve is large in structure and large in occupied space.

Disclosure of Invention

The invention aims to provide a butterfly valve and aims to solve the technical problems of poor sealing performance and large occupied space of the butterfly valve in the prior art.

In order to solve the technical problems, the technical scheme of the invention is as follows:

the butterfly valve comprises a valve pipe, a valve rod is rotatably connected to the valve pipe, a valve plate used for plugging the valve pipe is fixedly connected to the valve rod, two ends of the valve pipe are coaxially, rotatably and hermetically connected with end pipes, and a first connecting rod is fixedly connected between the two end pipes; both ends of the valve rod extend out of the valve pipe, one end of the valve rod is connected with a bevel gear, and a bevel gear ring meshed with the bevel gear is fixedly connected to the end pipe; the edge of the valve plate is provided with a sealing air bag, the other end of the valve rod is sleeved with a piston rod in a sliding mode, a first piston cavity communicated with the sealing air bag is arranged in the valve rod, a first piston is connected in the first piston cavity in a sliding mode, the inner end of the piston rod is fixedly connected to the first piston, the outer end of the piston rod is provided with a propping part, a stop block is fixedly connected to the end pipe, an arc-shaped track is arranged on the stop block, the arc-shaped track extends around the center of the valve pipe in an eccentric mode, a first spring is sleeved on the piston rod, and the propping part is driven by the first spring to be pressed into the arc-shaped track; the valve pipe is sleeved with a rotary cylinder at intervals, a second connecting rod is fixedly connected between the valve pipe and the rotary cylinder, and the rotary cylinder is connected with the two end pipes in a rotating and sealing manner.

Wherein, the valve pipe is internally provided with a second annular groove which is clamped with the sealing air bag.

Wherein, the border of valve plate is equipped with first ring channel, and air-bag includes first annular utricule, and first annular utricule cup joints in first ring channel, and first annular utricule inboard is equipped with the first joint portion of a plurality of, and the inboard of first ring channel is equipped with a plurality of draw-in groove, and first joint portion clamps in the draw-in groove.

Wherein, be equipped with the passageway in the valve plate, passageway intercommunication draw-in groove and first piston chamber, cup jointed first hard tube in the first joint portion, first hard tube intercommunication draw-in groove and first annular utricule.

Wherein, the internal interval of first annular utricule has cup jointed second annular utricule, and first annular utricule inboard is equipped with a plurality of second joint portion, and second joint portion extends to first annular utricule internally, and the rigid coupling in the inboard of second annular utricule, has cup jointed the second hard tube in the second joint portion, second hard tube intercommunication draw-in groove and second annular utricule.

Wherein, be equipped with the second piston chamber of intercommunication passageway in the valve rod, be equipped with the second piston in the second piston chamber, the piston rod rigid coupling is in the second piston.

The valve plate comprises a first circular plate and a second circular plate which are coaxially arranged at intervals, the first circular plate is fixedly connected with the valve rod, the sealing air bag is fixedly connected between the edges of the first circular plate and the second circular plate in a sealing mode, a plurality of telescopic pieces are uniformly distributed between the first circular plate and the second circular plate, each telescopic piece comprises a first cylinder body fixedly connected to the first circular plate and a second cylinder body fixedly connected to the second circular plate, the first cylinder body is provided with a sliding hole, an air hole communicated with the area between the first circular plate and the second circular plate is formed in the sliding hole, a sliding block and a second spring driving the sliding block to slide outwards in a sealing mode are arranged in the sliding hole, a first limiting ring used for limiting the sliding block is fixedly connected to an orifice of the sliding hole, and the second cylinder body is connected to the annular opening of the first limiting ring in a sealing mode in a sliding mode and fixedly connected with the sliding block.

Wherein, the top leaning part is provided with a ball sleeve, a first ball body is sleeved in the ball sleeve, and the first ball body is pressed against the arc-shaped track.

Wherein, the starting point end and the terminal point end of the arc track are both provided with a first positioning groove which is clamped with the first ball body.

The first connecting rod is provided with an installation block, the installation block is provided with an installation hole, an orifice of the installation hole is provided with a second limiting ring, a second ball body and a third spring are arranged in the installation hole, the end face of the end pipe is provided with a plurality of second positioning grooves, the plurality of second positioning grooves are circumferentially arranged around the end pipe, and the third spring drives the second ball body to pass through a ring opening of the second limiting ring and is clamped and matched with the second positioning grooves.

After the technical scheme is adopted, the invention has the beneficial effects that:

1. the outer part of the butterfly valve is of a pipe body structure, and the valve can be opened and closed by rotating the rotary cylinder positioned at the outermost part of the butterfly valve, so that the butterfly valve is small in overall occupied space and simple and convenient to assemble.

2. In the invention, when the valve pipe at the inner side rotates, the valve plate is driven to synchronously rotate open or close, and the sealing air bag at the edge of the valve plate synchronously contracts or expands.

3. The invention adopts the structure of double capsules and double piston cavities, so that the expansion and contraction actions of the sealed air bag are quick to respond, and the sealing is efficient.

4. The invention adopts a double-circular-plate combined structure, the first circular plate is fixed, the second circular plate is movable, and the second circular plate can synchronously drive the sealing air bag to further expand along with the increase of water pressure, thereby ensuring the sealing performance under the condition of high water pressure.

Drawings

FIG. 1 is an exploded view of a butterfly valve according to a first embodiment of the present invention;

FIG. 2 is a front view of FIG. 1 in combination;

FIG. 3 isbase:Sub>A cross-sectional view taken along line A-A of FIG. 2;

FIG. 4 is a cross-sectional view taken along line B-B of FIG. 2;

FIG. 5 is a schematic perspective view of a butterfly valve in a closed state according to an embodiment;

FIG. 6 is a schematic perspective view illustrating an opened state of a butterfly valve according to a second embodiment;

FIG. 7 is a cross-sectional view of a valve plate in a second embodiment of the butterfly valve of the invention;

FIG. 8 is an enlarged view of portion C of FIG. 7;

FIG. 9 is a partial cross-sectional view of a valve plate in a third butterfly valve embodiment of the invention;

FIG. 10 is a schematic view of a fourth embodiment of a butterfly valve according to the invention;

in the figure, 1-end pipe, 10-first flange joint, 11-second flange joint, 110-second positioning groove, 12-bevel gear ring, 13-stop, 130-arc rail, 131-first positioning groove, 14-first connecting rod, 2-valve pipe, 3-valve rod, 30-bevel gear, 31-piston rod, 310-abutting part, 311-first spring, 312-first ball, 32-first piston cavity, 33-first piston, 34-second piston cavity, 35-second piston, 4-valve plate, 40-first annular groove, 400-clamping groove, 41-first annular bag body, 410-first clamping part, 411-first hard pipe, 412-second clamping part, 413-second hard pipe, 42-channel, 43-second annular bag body, 44-first circular plate, 45-second circular plate, 46-third annular bag body, 47-telescopic part, 470-first cylinder, 471-second cylinder, 471-slide block, 473-second connecting rod, 473-second spring ring, 472-second spring, 53-spring ring, 52-spring ring, and spring ring holder 53-spring holder 52.

Detailed Description

The invention is further elucidated with reference to the drawing.

The orientations referred to in the specification are subject to the orientation of the butterfly valve in normal operation, the orientations of the butterfly valve in storage and transportation are not limited, and only relative position relationships are represented, but absolute position relationships are not represented.

Example one

As shown in fig. 1 to 6, the butterfly valve includes two end pipes 1, a valve pipe 2, a valve rod 3 and a valve plate 4, a first through hole is radially provided on a side wall of the valve pipe 2, the valve rod 3 is rotatably connected in the first through hole, and both ends of the valve rod 3 extend out of the valve pipe 2, and the valve rod 3 and the first through hole are sealed by a sealing bearing or a packing. Valve plate 4 is located valve pipe 2, and valve plate 4 is the disc, and valve plate 4 and valve pipe 2 clearance fit to valve plate 4 and valve rod 3 welding or integrated into one piece. As the valve rod 3 rotates, the valve plate 4 may laterally block the valve tube 2.

Two end pipes 1 are coaxially arranged at intervals, and the back end and the opposite end of each end pipe 1 are both first flange joints 10 used for connecting a liquid inlet pipe or a liquid outlet pipe. The looks remote site of two end pipes 1 is second flange joint 11, connects four ring-shaped first connecting rod 14 of arranging between two second flange joint 11, and first connecting rod 14 includes the body of rod, and the both ends of the body of rod respectively with two second flange joint 11 spiro unions, has cup jointed the cover body on the body of rod, the cover body support on the terminal surface of two second flange joint 11, realize the relatively fixed of two end pipes 1.

The valve pipe 2 is coaxially arranged between the two end pipes 1, the two ends of the valve pipe 2 are sleeved in the port of the second flange joint 11, and a rotary sealing ring is arranged between the valve pipe 2 and the end pipe 1, so that the valve pipe 2 can rotate relative to the end pipe 1.

One end of the valve rod 3, which is positioned outside the valve pipe 2, is coaxially and fixedly connected with a bevel gear 30, the end surface of the second flange joint 11 is fixedly connected with a bevel gear ring 12, and the bevel gear 30 is meshed with the bevel gear ring 12; the border of valve plate 4 is equipped with first ring channel 40, sealed gasbag is held to local in the first ring channel 40, sealed gasbag is used for sealing the clearance between valve plate 4 and the 2 inner walls of valve pipe, the other end that valve rod 3 is located outside the valve pipe 2 is equipped with first piston chamber 32, be equipped with passageway 42 in the valve plate 4, first piston chamber 32 is through passageway 42 intercommunication sealed gasbag, sliding connection has first piston 33 in the slider 472, the rigid coupling has piston rod 31 on the first piston 33, the outer end rigid coupling portion 310 of leaning on of piston rod 31, first spring 311 has been cup jointed on the piston rod 31, first spring 311 elastic support is leaning on between portion 310 and the 3 outer ends of valve rod. In this embodiment, a plurality of first clamping portions 410 arranged annularly are arranged on the inner side of the sealing airbag, a plurality of clamping grooves 400 are arranged on the inner side of the first annular groove 40, and the first clamping portions 410 are clamped in the corresponding clamping grooves 400, so that the sealing airbag is fixed in the first annular groove 40. In other ways, the inner side of the sealing bladder may be bonded to the wall of the first annular groove 40.

A stop block 13 is fixedly connected to the end surface of the second flange joint 11, an arc-shaped track 130 is arranged on one side of the stop block 13 facing the valve pipe 2, the arc-shaped track 130 is eccentrically extended around the center of the valve pipe 2, and the abutting portion 310 is pressed against the arc-shaped track 130 under the elastic driving of a first spring 311.

The valve pipe 2 is sleeved with the rotary cylinder 5 at intervals, at least two second connecting rods 50 are fixedly connected between the valve pipe 2 and the rotary cylinder 5, and the valve pipe 2 and the rotary cylinder 5 are relatively fixed through the two second connecting rods 50, so that the rotary cylinder 5 and the valve pipe 2 synchronously act; the barrel 5 is simultaneously sleeved outside the two end pipes 1, and a rotary sealing ring is arranged between the barrel 5 and the side walls of the two second flange joints 11, so that the barrel 5 can rotate around the axial direction, preferably, the outer wall of the barrel 5 is provided with a plurality of holding rods 51 which are arranged circumferentially, and operation of operators is facilitated.

When the valve rod 3 is used, an operator holds the holding rod 51 to rotate the rotary cylinder 5 forward by a specific angle to drive the valve tube 2 to rotate synchronously, and the bevel gear 30 rotates and advances along the bevel gear ring 12 due to the matching relationship between the bevel gear 30 and the bevel gear ring 12, so that the valve rod 3 rotates under the driving of the bevel gear 30 and the bevel gear ring 12, and the valve plate 4 is finally plugged on the valve tube 2; meanwhile, the abutting portion 310 travels from the starting end to the ending end along the arc-shaped track 130, in the process, the distance between the abutting portion 310 and the center of the valve plate 4 gradually decreases, the abutting portion 310 pushes the first piston 33 to slide towards the inner side of the first piston cavity 32, so that the first piston cavity gradually inflates towards the sealing air bag, the sealing air bag gradually expands to fill the fit clearance between the valve plate 4 and the valve pipe 2, and the butterfly valve is closed.

When the butterfly valve is opened, the operator holds the holding rod 51 to reversely rotate the rotary cylinder 5 by a specific angle, drives the valve plate 4 to reversely rotate by 90 degrees, so that the plate surface of the valve plate 4 and the axis of the valve pipe 2 are positioned in the same plane, fluid avoidance is formed, meanwhile, the top leaning part 310 resets to the starting point end along the arc-shaped track 130, drives the first piston 33 to reset, and thus the gas of the sealed air bag is gradually pumped out, so that the sealed air bag is synchronously contracted. Namely, the butterfly valve is opened.

In this embodiment, first joint portion 410 is the rubber material, is equipped with the boss on first joint portion 410, and draw-in groove 400 is the step hole, and after first joint portion 410 was impressed draw-in groove 400, the boss kept off to lean on the mesa in step hole, and it is spacing to form the boss through the mesa, avoids card protruding portion to deviate from the step hole is downthehole, only needs the pressure equipment can realize sealed gasbag's installation for sealed gasbag changes conveniently.

Furthermore, the clamping groove 400 is communicated with the first piston cavity 32, a first hard tube 411 is inserted into the inner side of the first clamping portion 410, a second through hole is formed in the first hard tube 411, the second through hole is communicated with the sealed air bag and the first piston cavity 32, and gas exhausted from the first piston cavity 32 sequentially enters the channel 42, the clamping groove 400 and the second through hole and finally enters the sealed air bag, so that the gas supply structure and the mounting structure of the sealed air bag are combined into a whole, and the structure is more compact; the first rigid tube 411 can always maintain the ventilation performance of the sealing balloon.

Further, the abutting portion 310 is provided with a ball sleeve in which the first ball 312 is fitted, a portion of the first ball 312 is located outside the ball sleeve, and the exposed portion is pressed against the inside of the arc-shaped rail 130. So that rolling friction is formed between the abutting part 310 and the arc-shaped track 130, and the abrasion of the components is reduced.

Furthermore, the starting end and the ending end of the arc-shaped track 130 are both provided with the first positioning grooves 131, the two first positioning grooves 131 are arc-shaped grooves, the arc-shaped grooves are in accordance with the partial profile modeling of the first ball body 312, so that the first ball body 312 can be clamped in the corresponding first positioning grooves 131 when moving to the starting end and the ending end of the arc-shaped track 130, elastic positioning is realized, deflection is avoided when the rotary cylinder 5 is not operated, and the butterfly valve sealing is influenced.

Furthermore, a second annular groove (not shown in the figure) which is matched with the sealing air bag in a clamping mode is arranged in the valve pipe 2, the sealing contact area is increased through the matching of the second annular groove and the sealing air bag, and the sealing effect is improved.

Example two

The difference between the first embodiment and the second embodiment is that, as shown in fig. 7 and fig. 8, the sealed airbag has a dual-bag structure, the second annular bag 43 is sleeved in the first annular bag 41, the inner side of the first annular bag 41 is provided with a plurality of second clamping portions 412, in this embodiment, the plurality of first clamping portions 410 and the plurality of second clamping portions 412 are arranged in a staggered manner, the second clamping portions 412 extend to the inner side of the first annular bag 41 and are fixedly connected with the inner side of the first annular bag 41, the first annular bag 41 and the second annular bag 43 are relatively fixed by the second clamping portions 412, and a cavity exists between the first annular bag 41 and the second annular bag 43. A second hard tube 413 is sleeved in the second clamping portion 412, and the second hard tube 413 is communicated with the clamping groove 400 and the second annular bag body 43. During inflation, gas is pressed into the channel 42 by the first piston 33, and then is simultaneously introduced into the first annular bladder 41 and the second annular bladder 43 through the first hard tube 411 and the second hard tube 413, so that the first annular bladder 41 and the second annular bladder 43 are inflated synchronously, the inflation efficiency of the first annular bladder 41 and the second annular bladder 43 is improved, and the inflation of the first annular bladder 41 is accelerated when the second annular bladder 43 is inflated. The response speed of the contraction and expansion of the sealing air bag is improved, and the sealing effect is improved.

Further, a second piston cavity 34 communicated with the channel 42 is formed in the valve rod 3, a second piston 35 is arranged in the second piston cavity 34, the piston rod 31 is communicated with the second piston cavity 34 and is fixedly connected with the second piston 35, when the piston rod 31 stretches, the first piston 33 and the second piston 35 are driven to synchronously slide, so that the first piston 33 and the second piston 35 synchronously slide, the first piston cavity 32 and the second piston cavity 34 synchronously supply air to the channel 42, the air supply amount is increased, and the expansion degree or the contraction degree of the first annular air bag and the second annular air bag is ensured. Further improve the response speed of the contraction and expansion of the sealed air bag and realize the quick opening and closing of the butterfly valve.

EXAMPLE III

The present embodiment is different from the first embodiment in that, as shown in fig. 9, the valve plate 4 includes a first circular plate 44 and a second circular plate 45 which are coaxially arranged at an interval, the first circular plate 44 is fixedly connected with the valve rod 3, the valve rod 3 is arranged along a radial direction of the first circular plate 44, the sealing airbag is a third annular capsule 46, the third annular capsule 46 is located between the first circular plate 44 and the second circular plate 45, and the third annular capsule 46 is adhered to the first circular plate 44 and the second circular plate 45, so that the first circular plate 44, the second circular plate 45 and the third annular capsule 46 form a sealing cavity.

A plurality of expansion elements 47 are uniformly distributed between the first circular plate 44 and the second circular plate 45, and each expansion element 47 includes a first column 470, a second column 471, a sliding block 472, a second spring 474 and a first limit ring 473. The first column 470 is coaxially disposed with the second column 471 and is aligned with the axial direction of the first circular plate 44 or the second circular plate 45. The first column 470 is vertically fixed to the plate surface of the first circular plate 44, and the second column 471 is vertically fixed to the plate surface of the second circular plate 45. The first column 470 is internally provided with a sliding hole, the sliding hole is internally and slidably connected with a sliding block 472, the sliding block 472 is provided with a sealing ring, the sealing between the sliding block 472 and the sliding hole is realized through the sealing ring, the sliding hole is internally and also internally provided with a second spring 474 which is elastically supported on the sliding block 472, the orifice of the sliding hole is fixedly connected with a first limiting ring 473, the first limiting ring 473 is used for limiting the sliding block 472, the sliding block 472 is prevented from being separated from the sliding hole, the sliding hole is provided with an air hole, and the air hole is communicated with a sealing cavity.

After the butterfly valve is closed, the third annular bag body 46 is inflated to fill the space between the valve plate 4 and the valve tube 2, when the water pressure in the end tube 1 is increased, the water in the valve tube 2 presses the second circular plate 45, so that the second circular plate 45 moves towards the first circular plate 44, at the moment, the third annular bag body 46 is pressed, the outer side of the third annular bag body 46 is further inflated towards the direction far away from the sealed cavity, meanwhile, the gas in the telescopic piece 47 is pressed into the sealed cavity, and the inner side of the third annular bag body 46 is limited from further inflating towards the sealed cavity. Thereby increasing the outward expansion of the third annular bladder 46 and improving the sealing performance of the butterfly valve, and the greater the water pressure, the greater the sealing strength.

Example four

The difference between the first embodiment and the second embodiment is that, as shown in fig. 10, the first connecting rod 14 is fixedly connected to the mounting block 52 through a bolt, the mounting block 52 is provided with a mounting hole, the mounting hole faces the end surface of the second flange joint 11, a second limiting ring 54 is provided at an opening of the mounting hole, a second ball 53 and a third spring 55 are provided in the mounting hole, the third spring 55 is elastically supported between the bottom of the mounting hole and the second ball 53, the end surface of the end pipe 1 is provided with a plurality of second positioning grooves 110, and the plurality of positioning grooves are circumferentially arranged around the end pipe 1. The third spring 55 drives the second ball 53 partially through the annular opening of the second retainer ring 54 and snaps into the corresponding second detent 110.

In the rotation process of the valve pipe 2, the second ball 53 can be clamped with different second positioning grooves 110 to realize elastic positioning, so that the butterfly valve can be stopped at a specific position preferably, the number of the mounting holes is two, one second flange joint 11 corresponds to one mounting hole, so that the mounting block 52 can be connected with the two second flange joints 11 at the same time in a positioning manner, and the positioning stability is improved.

The present invention is not limited to the above-described embodiments, and various modifications made by those skilled in the art without inventive skill from the above-described conception fall within the scope of the present invention.

Claims

1. The butterfly valve comprises a valve pipe, a valve rod is rotatably connected on the valve pipe, a valve plate for plugging the valve pipe is fixedly connected on the valve rod, and the butterfly valve is characterized in that,

two ends of the valve pipe are coaxially, rotatably and hermetically connected with end pipes, and a first connecting rod is fixedly connected between the two end pipes;

both ends of the valve rod extend out of the valve pipe, one end of the valve rod is connected with a bevel gear, and a bevel gear ring meshed with the bevel gear is fixedly connected to the end pipe;

the edge of the valve plate is provided with a sealing air bag, the other end of the valve rod is sleeved with a piston rod in a sliding manner, a first piston cavity communicated with the sealing air bag is arranged in the valve rod, a first piston is connected in the first piston cavity in a sliding manner, the inner end of the piston rod is fixedly connected with the first piston, the outer end of the piston rod is provided with a propping part, the end pipe is fixedly connected with a stop block, the stop block is provided with an arc-shaped track, the arc-shaped track eccentrically extends around the center of the valve pipe, the piston rod is sleeved with a first spring, and the propping part is driven by the first spring to be pressed in the arc-shaped track;

the valve pipe outer interval cover is equipped with revolves a section of thick bamboo, the valve pipe with the rigid coupling has the second connecting rod between revolving the section of thick bamboo, revolve a section of thick bamboo and two end pipe rotary seal and be connected.

2. The butterfly valve of claim 1 wherein the valve tube has a second annular groove formed therein for snap-fitting with the sealing bladder.

3. The butterfly valve of claim 1, wherein a first annular groove is formed in an edge of the valve plate, the air bag comprises a first annular bag body, the first annular bag body is sleeved in the first annular groove, a plurality of first clamping portions are arranged on the inner side of the first annular bag body, a plurality of clamping grooves are arranged on the inner side of the first annular groove, and the first clamping portions are clamped in the clamping grooves.

4. The butterfly valve of claim 3 wherein a passage is defined in the valve plate, the passage communicating with the slot and the first piston chamber, a first rigid tube received in the first retaining portion, the first rigid tube communicating with the slot and the first annular bladder.

5. The butterfly valve of claim 4, wherein a second annular bag body is sleeved in the first annular bag body at intervals, a plurality of second clamping portions are arranged on the inner side of the first annular bag body, the second clamping portions extend into the first annular bag body and are fixedly connected to the inner side of the second annular bag body, a second hard tube is sleeved in the second clamping portions, and the second hard tube is communicated with the clamping grooves and the second annular bag body.

6. The butterfly valve of claim 5 wherein a second piston chamber is defined in the valve stem in communication with the passage, a second piston is defined in the second piston chamber, and the piston rod is secured to the second piston.

7. The butterfly valve of claim 1, wherein the valve plate includes a first circular plate and a second circular plate coaxially disposed at an interval, the first circular plate is fixedly connected to the valve rod, the sealing airbag is fixedly connected between edges of the first circular plate and the second circular plate, a plurality of expansion members are uniformly distributed between the first circular plate and the second circular plate, each expansion member includes a first cylinder fixedly connected to the first circular plate and a second cylinder fixedly connected to the second circular plate, the first cylinder is provided with a sliding hole, the sliding hole is provided with an air hole communicating an area between the first circular plate and the second circular plate, the sliding hole is provided with a slider and a second spring driving the slider to slide outwards in a sealing manner, a first limiting ring for limiting the slider is fixedly connected to an orifice of the sliding hole, and the second cylinder is fixedly connected to an orifice of the first limiting ring in a sealing manner and fixedly connected to the slider.

8. The butterfly valve of claim 1 wherein said abutment portion has a ball sleeve with a first ball received therein, said first ball bearing against an arcuate track.

9. The butterfly valve of claim 8 wherein the beginning and ending ends of the arcuate track each have a first detent for engaging the first ball.

10. The butterfly valve of claim 1 wherein the first connecting rod has a mounting block with a mounting hole, the mounting hole has a second retaining ring, the mounting hole has a second ball and a third spring, the end surface of the end tube has a plurality of second positioning grooves circumferentially arranged around the end tube, and the third spring drives the second ball partially through the opening of the second retaining ring and engages with the second positioning grooves.